The SierraTuff series are good quality and make great all-around multipurpose bits. You can use them to drill in any material including soft materials such as concrete and hard materials like solid quartz. Another great aspect is that during out testing usually 95% of the rock dust was removed during the drilling process thanks to the superior flute design; This means less time pumping rock dust if you are going to blast dry. The SierraTuff bits work in any SDS and SDS+ drill, you can also use an SDS Max with an adapter however this is a slower system due to the lower BPM produced by the SDS Max.
The (21"x23") SierraTuff SDS bit is great for overdrilling to use the hydraulic effect by adding water. For more information about why we sell bits of varying length check out our video section. (Videos Coming Soon)
For the length notation of (21"x23"): 21" notes the usable length and 23" notes the total length of the bit.